Research
Yield Stability in Forage Maize Across Selected Test-Environments
Assessing new maize cultivars requires studying both yield and stability performance across the major range of environments. Four trials were conducted in Sudan (Africa) during 2013 – 2014. Nine maize genotypes were investigated for forage yield stability across 8 test-environments created by a combination of 2 levels of location, season and watering regime assumed to impose respective effects of salt, heat and water stresses. Wricke’s ecovalence, Eberhart-Russell and AMMI stability models were employed to study yield stability. The genotypes and watering regimes were arranged in RCB design in split-plot experiment. The study revealed maize hybrids having broad and specific responses to the studied environments with most genotypes showing consistent stability performance in the three models. Two of the 3 top-yielding hybrids showed relative stability whereas the third one exhibited specific adaptability to low yielding environments. It was concluded that yield stability could be better investigated if the varieties are purposely subjected to major factors affecting yield in a given domain. Different stability models were recommended to avoid limitations arising from using a single model.
Effect of Nitrogen and Variety on Quality Performance of Rhodes Grass (Chloris gayana Kunth) in the Sudan
An experiment was conducted in Shambat (2016- 2017) in the demonstration farm of the College of Agricultural Studies, Sudan University of Science and Technology to study the effect of variety and nitrogen fertilization on the quality performance of Rhodes grass. Two Rhodess grass varieties (Fine Cut and Reclaimer) and three nitrogen levels (60kgN/ha, 120kg N/ha and Control= 0.0kgN/ha) were investigated across seven cuts. The treatments were studied as factorial arrangement in Completely Randomized Design. Proximate analysis for Neutral Detergent Fiber (NDF), Acid Detergent Fiber (ADF) and Crude Protein(CP) was carried out. Differences between varieties were not significant for Neutral Detergent Fiber (NDF) Acid Detergent Fiber (ADF) and Crude protein (CP). Nitrogen dose and cutting age have a significant effect on NDF and ADF. Crude protein was significantly affected by cutting age but not nitrogen dose. The interaction effect of nitrogen dose and cutting age was significant for NDF and ADF. The dose 60kgN/ha gave desirable ADF percentage compared to 120kgN/ha whereas the opposite is true for NDF. Cutting age at 182 and 268 days resulted in desirable ADF percentage compared to 75 day whereas the opposite is true for NDF. Crude protein was better at cutting age of 75 day than 182 day. It was concluded that cutting age and nitrogen fertilization have significant impact on Rhodes grass digestibility and intake potential. More research is needed to study the impact of nitrogen fertilization on crude protein of Rhodes grass.
Effect of Nitrogen and Variety on Agronomic Performance of Rhodes Grass (Chloris gayana Kunth) in the Sudan
An experiment was conducted in Shambat (2016- 2017) in the demonstration farm of the College of Agricultural Studies, Sudan University for Science and Technology, to study the effect of variety and nitrogen fertilization on the agronomic performance of Rhodes grass. Two Rhodess grass varieties (Fine cut and Reclaimer) and 2 nitrogen doses plus control were studied across seven cuts. The treatments were replicated four times in split plot experiment with fertilizer doses assigned to the main plots and the varieties to the subplots. The data collected included forage yield, plant height and days to 50% flowering. Differences between varieties and their interaction with cuts were not significant for forage yield. Differences between fertilizer doses for forage yield and their interaction with cuts were highly significant. The nitrogen dose 120kgN/ha significantly increased for age yield and plant height over 60kgN/ha and the control with yield increment of 118%. The dose 60kgN/ha failed to give significant increase in yield over the control. The highest forage yield was obtained in the first cut after establishment then started to decease. The nitrogen dose 120kgN/ha maintained comparatively high yield throughout the subsequent cuts. It was concluded that nitrogen application has significant positive impact on productivity of Rhodes grass. Future research should focus on optimizing management of nitrogen dose across cuts. Lack of differences between Rhodes grass varieties in forage yield was attributed to the narrow genetic base of the diploid group. More attention should be given to Tetraploid varieties (Callide, Samford) to enhance productivity of the dairy farms.
